Flat cables were developed for use in the transmission of relatively low-frequency digital or analog signals, and are widely used in various types of electronic devices and devices using electronics In particular, since flat cables are extremely thin, such cables are superior in terms of the space factor obtained; furthermore, since flat cables also have good flexibility, such cable are suitable not only for compact, high-density connections but also for mutual connections between movable parts and fixed parts.
Flat cable connectors also include vertical type connectors that have an insulating housing and contacts that are perpendicular to the circuit board; however, horizontal type connectors that utilize the compact, high-density characteristics of flat cables are more common. For example, applications are common in which a pair of flat cable connectors are connected to both ends of a flat cable, and this cable is used to connect two circuit boards that are parallel to each other or positioned in an arbitrary angular relationship.
Common conventional examples of such horizontal type flat cable connectors are described in (for example) Japanese Utility Model Application Kokoku No. 5-32945, Japanese Patent Application Kokai No. 3-266384 and Japanese Patent Application Kokai No. 5-251140.
In such conventional flat cable connectors, beam-form contacts or contacts having the shape of a tuning fork with one elastic arm are fastened parallel to each other in a row along an opening formed in an insulating housing. One end of the flat cable is inserted into this contact row via the opening in the insulating housing. Furthermore, since flat cables are extremely thin and flexible, a reinforcing plate is ordinarily attached to one end of the flat cable on the opposite side from the conductors in order to endow the cable with some rigidity. However, stable contact with a sufficient contact pressure between the respective conductors of such a flat cable and the contacts of the connector cannot be obtained merely by inserting one end of the flat cable into the opening formed in the insulating housing. Generally, therefore, it is necessary to insure a sufficient contact pressure by press-fitting a slider made of an insulating plastic inside the opening so that the conductors of the flat cable are pressed against the contacts by the tongue part of this slider.
A typical example of such a conventional flat cable connector will be described in further detail with reference to FIGS. 4(A) and 4(B). Here, the flat cable connector 1 has a relatively thin rectangular insulating housing 2, and contacts 4 that have two arms are fastened by press-fitting from the rear end of the connector inside contact receiving holes 3 that pass completely through the connector from the front end to the rear end. The leading end portion of a flat cable 5 is inserted between the arms of the respective contacts 4 via an opening in the front surface of the insulating housing 2. Furthermore, a slider 6 having a tongue part is pushed in from the front surface of the insulating housing 2, so that the conductors of the flat cable 6 are pressed against the contacts 4 by the tongue part.
Here, as is clear from FIG. 4(A), it is necessary that the slider 6 be securely anchored inside the insulating housing 2 after insertion so that contacts 4 constantly maintain an appropriate contact pressure against the conductors of flat cable 5. For this reason, it is necessary to dispose latching arms and engaging parts between the sides of slider 6 and the facing insulating housing 2 so that both parts are fastened by latching. As is clear from FIG. 4(A), such latching parts occupy a considerable portion of the overall width of the insulating housing 2. This is also true in the conventional examples mentioned above. When the number of conductors in the flat cable is increased so that the width of the flat cable is increased, the area occupied by the latching parts becomes smaller in relative terms; however, in view of the strong demand for light weight, thinness and compactness in recent electronic devices, the area occupied by such latching parts cannot be ignored.
Furthermore, in the case of Japanese Patent Application Kokai No. 5-251140 mentioned above, a flat cable is split into a plurality of flat cables, and a connector module is formed for each of these flat cables. Latching parts are formed on sliders for each module, and a flat cable connector is obtained in which latching engagement is accomplished by means of a plurality of latching arms formed by a metal cover that accommodates a plurality of modules. However, as a result of such modularization, a certain amount of dead space is unavoidably created between the modules, so that an increase in density is hindered